Sun-cured tobacco, Bastam, Iran Curing and subsequent growing old allow for your slow oxidation and degradation of carotenoids in tobacco leaf. This generates sure compounds within the tobacco leaves and gives a sweet hay, tea, rose oil, or fruity aromatic flavor that contributes for the "smoothness" from the smoke. https://broadfar.com/non-combusted-cigarettes-a-safer-alternative-or-just-a-myth/